Balanced to Unbalanced Converter-2 channel

Ideal Use Cases

The RDL FP-BUC2 is a connectorized, two-channel audio converter designed for balanced-to-unbalanced signal conversion. Its two identical circuits support either stereo or dual-mono operation, making the unit suitable for systems that need to connect balanced audio sources with unbalanced lines. Separate adjustment for each channel also supports applications where left and right levels, or two independent mono signals, require individual alignment.

The FP-BUC2 can be used in cabinet, shelf, or rack-mounted installations. Its balanced bridging inputs and 75 Ω unbalanced outputs allow it to interface with 600 Ω or 10 kΩ unbalanced lines. This combination makes it useful wherever two channels of controlled level conversion are required without combining or linking the channels.

Why Choose This Model

This model combines adjustable output-level alignment with specified low-noise and low-distortion performance. Gain is adjustable by ±6 dB relative to a −10 dBV output for a +4 dBu input, with a separate control for each channel. The accepted input range is −2 dBu to +10 dBu for a −10 dBV output, providing a defined operating range for integrating balanced and unbalanced equipment.

The two circuits are identical, so the unit can serve a conventional stereo signal path or operate as two independent mono converters. A 20 kΩ balanced bridging input impedance helps the FP-BUC2 receive balanced signals, while the unbalanced output configuration provides the required destination format.

Installation and Integration

The FLAT-PAK format supports cabinet, shelf, or rack mounting. The enclosure measures 1.29 inches high by 3.25 inches wide by 4.07 inches long, equivalent to 3.28 by 8.26 by 10.34 centimeters. These documented dimensions make it possible to plan equipment placement before installation.

Power requirements are ground-referenced 24 Vdc at 50 mA. The recommended PS-24AS power supply for the USA or PS-24AX for international use is not included. The specified ambient operating range is 0° C to 55° C. During setup, each channel can be trimmed separately to establish the required conversion level. Connector types are not identified in the supplied product data.

Performance Highlights

The FP-BUC2 has a specified frequency response of 10 Hz to 40 kHz within ±0.1 dB. THD+N is less than 0.005% from 10 Hz to 40 kHz, and IMD is also specified at less than 0.005%. Headroom is greater than 18 dB at the rated −10 dBV output level.

Noise is specified below −90 dB when referred to −10 dBV over 20 Hz to 20 kHz, with a typical A-weighted figure of −95 dB relative to −10 dBV. Common-mode rejection is greater than 50 dB from 20 Hz to 5 kHz. Crosstalk is better than −90 dB from 20 Hz to 20 kHz, supporting separation between the two conversion channels.

Each input uses a balanced bridging configuration with 20 kΩ impedance. Each output is unbalanced with 75 Ω impedance and is specified to drive either 600 Ω or 10 kΩ unbalanced lines. Together, these characteristics define the FP-BUC2 as a dedicated interface for two-channel balanced-to-unbalanced conversion.

What Makes It Different

The FP-BUC2 focuses specifically on stereo or dual-mono conversion rather than combining both channels into a single signal path. Independent gain adjustment allows each circuit to be aligned on its own, while the identical channel design supports consistent use across a stereo pair. Its combination of wide 10 Hz to 40 kHz frequency response, less than 0.005% THD+N and IMD, greater than 18 dB headroom, and better than −90 dB crosstalk provides clearly documented performance parameters for system planning.

It also brings the mounting flexibility of the RDL FLAT-PAK format, allowing the same converter to be incorporated into cabinet, shelf, or rack-based installations.

Final Assessment

The RDL FP-BUC2 is a focused two-channel solution for converting balanced audio to unbalanced output. It provides stereo or dual-mono operation, separate ±6 dB channel adjustments, balanced bridging inputs, and 75 Ω unbalanced outputs capable of driving 600 Ω or 10 kΩ lines. For installations requiring documented low-noise, low-distortion conversion in a cabinet-, shelf-, or rack-mountable format, the FP-BUC2 offers a clearly specified signal-interface option. A compatible 24 Vdc power supply must be obtained separately.